1. Field of the Invention
The present invention relates to a sensor device capable of reducing measurement processing time.
2. Description of the Related Art
There are conventionally known sensor devices for measuring displacements, lengths, angles and the like of a variety of objects to be measured. For example, a conventional displacement sensor device comprises: a light-transmitting portion for irradiating an object to be measured with slit light by driving a light-transmitting element such as a laser diode; a light-receiving portion for receiving the slit light having been transmitted from the light-transmitting portion and reflected by the object to be measured; a calculating means for calculating a distance to the object to be measured; and an outputting means for outputting the distance to the object to be measured which was calculated by the calculating means (see e.g., International Publication pamphlet No. 01/57471).
The case is assumed, as shown in FIG. 15, that objects [1], [2] and [3] to be measured are conveyed along a line (from the right to the left in the figure), a sensor head portion 1501 of a displacement sensor device irradiates each of the objects to be measured with slit light in a vertical direction to the direction of conveying the objects to be measured (or the up and down direction in the figure) and then receives the light reflected by each of the objects to be measured. In FIG. 15, when it is considered that the object [1] to be measured is arranged in a standard position on the line, the object [2] to be measured is considered to be arranged on a closer side to the sensor head portion 1501 while the object [3] to be measured is considered to be arranged on a farther side to the sensor head portion 1501. As thus described, there are some cases where variations occur in arrangement of objects to be measured on a line.
As shown in FIG. 16, in a rectangular visual field Z (light-receiving face) of a two-dimensional image pickup element built in the sensor head portion 1501, irradiated-light images [1], [2] and [3] are arranged to correspond to the objects to be measured. In the figure, the left side is closer, whereas the right side is farther, to the sensor head portion 1501. While a horizontal line (in a displacement measuring direction) has been set along the longitudinal direction of the rectangular visual field Z, a vertical line (in an extending direction of the irradiated-light images) orthogonal to the set horizontal line has been allocated. In this case, a rectangular measurement area surrounded with a broken line is set as a normal measurement area so as to measure the irradiated-light images [1], [2] and [3].
When the variation area A shown in FIG. 15 is wide, the measurement area widens, or it becomes necessary to previously widen the measurement area shown in FIG. 16 to correspond to the variation area A. There is therefore a disadvantage that the wider the measurement area is, the longer the time required for reading out data is.
The present invention was made focusing attention on such a conventional problem, and has an object to provide a sensor device capable of reading out and arithmetically processing data at high speed.
Still another object, as well as action effect, of the present invention would be readily understood by a skilled person in the art by referring to the following description.